Captain David Seath, originally from Cowdenbeath in Fife, was a fire support team commander in 29 Commando Regiment Royal Artillery.

Captain David Seath appearing in archive footageCredit:
Forces TV

He was filmed by Forces TV last October working with the Scottish charity War Blinded.

The 31-year-old suffered a suspected cardiac arrest while running the 26.2-mile course on Sunday. He leaves behind his parents Libby and Pete, brother Gary and girlfriend Gaby Schoenberger.

Watch | Doctor: More chance of lightning strike than dying in marathon

01:38

His commanding officer Lt Col Jon Cresswell paid tribute to Captain Seath, describing him as "a great soldier, great leader of men, charismatic and a performer".

More than £55,000 has since been raised for his chosen charity by his friends and colleagues who are vowing to "complete what he started" - finishing the marathon course for him and continuing to raise cash for Help For Heroes.